U.S. patent application number 13/517389 was filed with the patent office on 2012-10-04 for polyurethane-based sealant for insulated glass units.
Invention is credited to Laura A. Grier, William A. Koonce, Dwight D. Latham, Bindushree Radhakrishnan, Paul D. Ries, Matthias Schaefer.
Application Number | 20120253001 13/517389 |
Document ID | / |
Family ID | 43413666 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120253001 |
Kind Code |
A1 |
Radhakrishnan; Bindushree ;
et al. |
October 4, 2012 |
Polyurethane-Based Sealant for Insulated Glass Units
Abstract
Insulated glass units are sealed with polyurethane made using a
natural oil-based polyol (NOBP). In one embodiment the NOBP is made
using a monol-rich monomer containing high levels of mono-hydroxy
functional fatty acid methyl esters. Insulated glass sealants based
on these compounds provide enhanced resistance to UV and oxidative
degradation as compared to conventional products while still
providing the required barrier and mechanical properties.
Inventors: |
Radhakrishnan; Bindushree;
(Lake Jackson, TX) ; Latham; Dwight D.; (Clute,
TX) ; Grier; Laura A.; (Brazoria, TX) ;
Koonce; William A.; (Pearland, TX) ; Schaefer;
Matthias; (Terneuzen, NL) ; Ries; Paul D.;
(Midland, MI) |
Family ID: |
43413666 |
Appl. No.: |
13/517389 |
Filed: |
November 15, 2010 |
PCT Filed: |
November 15, 2010 |
PCT NO: |
PCT/US10/56677 |
371 Date: |
June 20, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61288747 |
Dec 21, 2009 |
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Current U.S.
Class: |
528/85 ;
528/74.5 |
Current CPC
Class: |
C08G 18/10 20130101;
C08K 5/10 20130101; C08G 18/6674 20130101; C09K 3/1021 20130101;
C08G 2190/00 20130101; C08K 5/10 20130101; C08G 18/4891 20130101;
C08G 18/36 20130101; C08G 18/4288 20130101; C08L 75/04 20130101;
C08G 18/664 20130101; C08G 18/10 20130101 |
Class at
Publication: |
528/85 ;
528/74.5 |
International
Class: |
C08G 18/32 20060101
C08G018/32; C08G 18/34 20060101 C08G018/34 |
Claims
1. An insulating glass unit comprising a polyurethane-based sealant
that comprises at least a reaction product of at least one
isocyanate and at least one polyol blend, the blend comprising a
natural oil-based polyol (NOBP).
2. The insulating glass unit of claim in which the at least one
NOBP is made using a monol-rich monomer derived from natural
oil.
3. The insulating glass unit of claim 1 in which the at least one
NOBP comprises at least two natural oil moieties separated by a
molecular structure having at least about 19 ether groups or
separated by a polyether molecular structure having an equivalent
weight of at least about 480.
4. The insulating glass unit of claim 3 in which the sealant
comprises the reaction product of at least one prepolymer
comprising the reaction product of a first polyol and the at least
one isocyanate and a second polyol, in which the first and second
polyol may be the same or different and at least one of the first
polyol and the second polyol comprises the at least one polyol
blend comprising a NOBP.
5. The insulating glass unit of claim 4 in which the polyol blend
further comprises a chain extender.
6. The insulating glass unit of claim 5 in which the chain extender
comprises at least one of 2-ethyl-1,3-hexanediol and
1,4-butanediol.
7. The insulating glass unit of claim 1 in which the NOBP is
derived from a monomer composition comprising at least 85 weight
percent (wt %) mono-hydroxy functional fatty acid alkyl ester.
8. The insulating glass unit of claim 7 in which the mono-hydroxy
functional fatty acid alkyl ester is mono-hydroxy functional fatty
acid methyl ester.
9. The insulating glass unit of claim 8 in which the mono-hydroxy
functional fatty acid methyl ester is derived from soy oil.
10. The insulating glass unit of claim 1 in which the
polyurethane-based sealant is present as a single seal.
11. The insulating glass unit of claim 1 in which the
polyurethane-based sealant is present as at least one seal of a
dual seal system.
Description
FIELD OF THE INVENTION
[0001] This invention relates to insulating glass. In one aspect
the invention relates to insulating glass sealed with a
polyurethane-based sealant while in another aspect, the invention
relates to such sealants in which the polyurethane is made using
natural oil-based polyols (NOBP).
BACKGROUND OF THE INVENTION
[0002] Insulating (or insulated) glass (IG) units comprise two
parallel sheets of glass held apart by spacer bars. The cavity
formed between the sheets of glass is filled with inert gas to help
reduce heat and sound transmission. Typically two different types
of sealants are used to join the glass to the spacer bars. The
innermost or the primary sealant joins the space bars to the glass
sheets, and serves as a barrier against escape or egress of the
inert gas from the cavity as well as a barrier against the entry or
ingress of moisture vapor into the cavity. Thermoplastic
polyisobutylene is the most common primary sealant. However this
material lacks mechanical strength and it exhibits comparably less
adhesion than the outermost or secondary sealant. As such, one
function of the secondary sealant is to provide mechanical strength
to the unit and to prevent rupture of the primary sealant during
the natural thermal cycles to which the unit is exposed.
[0003] Because of its good mechanical properties, polyurethane,
particularly polyurethane that is based on a hydrophobic
polybutadiene-based polyol, is a commonly used secondary sealant.
However, such polyurethanes lack good UV stability and gas
retention properties. They also contribute to a strong odor to
these systems. Eliminating or reducing these drawbacks without
significantly diminishing the mechanical properties of polyurethane
for these applications, at a competitive price, is a topic of
active research.
SUMMARY OF THE INVENTION
[0004] In one embodiment the invention is a polyurethane-based
sealant for an insulated glass unit, the polyurethane made using a
NOBP which is made using monol-rich monomer, i.e., monomer from
natural oil containing high levels of mono-hydroxy functional fatty
acid alkyl esters, typically methyl esters. In one embodiment the
high levels of mono-hydroxy functional fatty acid alkyl esters are
naturally present in the natural oil while in another embodiment,
the high levels of mono-hydroxy functional fatty acid alkyl esters
are the result of subjecting the natural oil to a concentration or
purification process, e.g., distillation. In one embodiment the
natural oil is derived from soybeans.
[0005] In one embodiment the invention is an IG unit comprising a
sealant composition comprising polyurethane made using NOBP
monol-rich monomer. Insulated glass sealants based on these
compounds provide enhanced resistance to UV and oxidative
degradation as compared to conventional products while still
providing the required barrier and mechanical properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1A is a DMTA plot of polybutadiene-based polyurethane
of Comparative Example A.
[0007] FIG. 1B is a DMTA plot of monol-rich monomer NOBP-based
polyurethane of Example 4.
[0008] FIG. 2A is a bar graph reporting the percent elongation of
the polybutadiene-based polyurethane of Example A and the
monol-rich monomer NOBP-based polyurethane of Example 4 before and
after water exposure.
[0009] FIG. 2B is a bar graph reporting the tensile strength in psi
of the polybutadiene-based polyurethane of Example A and the
monol-rich monomer NOBP-based polyurethane of Example 4 before and
after water exposure.
[0010] FIG. 3 is a bar graph reporting the effect of weathering on
the mechanical properties of the polybutadiene-based polyurethane
of Example A and the monol-rich monomer NOBP-based polyurethane of
Example 4 film plaques.
[0011] FIG. 4A is a bar graph reporting the MVTR of the
polybutadiene-based polyurethane of Example A and the monol-rich
monomer NOBP-based polyurethane of Example 4 film plaques.
[0012] FIG. 4B is a bar graph reporting the OTR of the
polybutadiene-based polyurethane of Example A and the monol-rich
monomer NOBP-based polyurethane of Example 4 film plaques.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] Unless stated to the contrary, implicit from the context, or
customary in the art, all parts and percents are based on weight
and all test methods are current as of the filing date of this
disclosure. For purposes of United States patent practice, the
contents of any referenced patent, patent application or
publication are incorporated by reference in their entirety (or its
equivalent US version is so incorporated by reference) especially
with respect to the disclosure of synthetic techniques, definitions
(to the extent not inconsistent with any definitions specifically
provided in this disclosure), and general knowledge in the art.
[0014] The numerical ranges in this disclosure are approximate, and
thus may include values outside of the range unless otherwise
indicated. Numerical ranges include all values from and including
the lower and the upper values, in increments of one unit, provided
that there is a separation of at least two units between any lower
value and any higher value. As an example, if a compositional,
physical or other property, such as, for example, molecular weight,
viscosity, etc., is from 100 to 1,000, it is intended that all
individual values, such as 100, 101, 102, etc., and sub ranges,
such as 100 to 144, 155 to 170, 197 to 200, etc., are expressly
enumerated. For ranges containing values which are less than one or
containing fractional numbers greater than one (e.g., 1.1, 1.5,
etc.), one unit is considered to be 0.0001, 0.001, 0.01 or 0.1, as
appropriate. For ranges containing single digit numbers less than
ten (e.g., 1 to 5), one unit is typically considered to be 0.1.
These are only examples of what is specifically intended, and all
possible combinations of numerical values between the lowest value
and the highest value enumerated, are to be considered to be
expressly stated in this disclosure. Numerical ranges are provided
within this disclosure for, among other things, the relative
amounts of components in the sealant compositions.
[0015] "Composition", "formulation" and like terms means a mixture
or blend of two or more components. In the context of the
monol-rich monomer, the composition includes the mono-hydroxy
functional fatty acid alkyl ester and the other components
naturally found in natural oil. In the context of a mix or blend of
materials from which an IG sealant is prepared, the composition
includes all the components of the mix, e.g., polyurethane and any
optional components such as antioxidant, UV stabilizer, rheology
modifiers, fillers, optional polymers, and the like.
[0016] "Monol-rich monomer" and like terms means a composition
comprising at least 50, typically at least 75 and more typically at
least 85, weight percent (wt %) mono-hydroxy functional fatty acid
alkyl ester such as, but not limited to, that of formula I:
##STR00001##
The length of the carbon backbone of formula I can vary, e.g.,
C.sub.12-C.sub.20, but it is typically C.sub.18, as can the
placement of the hydroxymethyl group along its length. The
monol-rich monomer used in the practice of this invention can
comprise a mixture of mono-hydroxy functional fatty acid alkyl
esters varying in both carbon backbone length and hydroxy group
placement along the length of the various carbon backbones. The
monomer can also be an alkyl ester other than methyl, e.g., a
C.sub.2-C.sub.8 alkyl ester. Other components of the composition
include, but are not limited to, poly (e.g., di-, tri-, tetra-,
etc.) hydroxy functional fatty acid alkyl esters.
[0017] "Monol-rich monomer NOBP", "NOBP made using monol-rich
monomer" and like terms means a NOBP made using a monol-rich
monomer.
[0018] "Monol-rich monomer NOBP polyurethane" and like terms means
a polyurethane made using a monol-rich monomer NOBP.
[0019] Natural Oil-Based Polyols
[0020] Natural oil-based polyols (NOBP) are polyols based on or
derived from renewable feedstock resources such as natural and/or
genetically modified plant vegetable seed oils and/or animal source
fats. Such oils and/or fats are generally comprised of
triglycerides, that is, fatty acids linked together with glycerol.
Preferred are vegetable oils that have at least about 70 percent
unsaturated fatty acids in the triglyceride. Preferably the natural
product contains at least 85 percent by weight unsaturated fatty
acids. Examples of preferred vegetable oils include, but are not
limited to, those from castor, soybean, olive, peanut, rapeseed,
corn, sesame, cotton, canola, safflower, linseed, palm, grapeseed,
black caraway, pumpkin kernel, borage seed, wood germ, apricot
kernel, pistachio, almond, macadamia nut, avocado, sea buckthorn,
hemp, hazelnut, evening primrose, wild rose, thistle, walnut,
sunflower, jatropha seed oils, or a combination of two or more of
these oils. Examples of animal products include lard, beef tallow,
fish oils and mixtures of two or more of these products.
Additionally, oils obtained from organisms such as algae may also
be used. Combination of vegetable, algae, and animal based
oils/fats may also be used.
[0021] The modified natural oil derived polyols may be obtained by
a multistep process in which the animal or vegetable oils/fats are
subjected to transesterification and the constituent fatty acids
recovered. This step is followed by hydroformylating carbon-carbon
double bonds in the constituent fatty acids to form hydroxymethyl
groups. Suitable hydroformylation methods are described in U.S.
Pat. Nos. 4,731,486 and 4,633,021, for example, and in U.S.
Published Patent Application 2006/0193802. The hydroxymethylated
fatty acids are "monomers" which form one of the building blocks
for the natural oil based polyol. The monomers may be a single kind
of hydroxymethylated fatty acid and/or hydroxymethylated fatty acid
methyl ester, such as hydroxymethylated oleic acid or methylester
thereof, hydroxymethylated linoleic acid or methylester thereof,
hydroxymethylated linolenic acid or methylester thereof, .alpha.-
and .gamma.-linolenic acid or methyl ester thereof, myristoleic
acid or methyl ester thereof, palmitoleic acid or methyl ester
thereof, oleic acid or methyl ester thereof, vaccenic acid or
methyl ester thereof, petroselinic acid or methyl ester thereof,
gadoleic acid or methyl ester thereof, erucic acid or methyl ester
thereof, nervonic acid or methyl ester thereof, stearidonic acid or
methyl ester thereof, arachidonic acid or methyl ester thereof,
timnodonic acid or methyl ester thereof, clupanodonic acid or
methyl ester thereof, cervonic acid or methyl ester thereof, or
hydroxymethylated ricinoleic acid or methylester thereof. In one
embodiment the monomer is hydroformylated methyloelate.
Alternatively, the monomer may be the product of hydroformylating
the mixture of fatty acids recovered from transesterification
process of the animal or vegetable oils/fats. In one embodiment the
monomer is hydrogenated soy bean fatty acids. In another embodiment
the monomer is hydrogenated castor bean fatty acids. In another
embodiment the monomer may be a mixture of selected
hydroxymethylated fatty acids or methylesters thereof.
[0022] In one embodiment the NOBP is monol-rich monomer NOBP. The
source of the monol-rich monomer can vary widely and includes, but
is not limited to, high oleic feedstock or distillation of a low
oleic feedstock, e.g., a natural seed oil such as soy as, for
example, disclosed in co-pending application "PURIFICATION OF
HYDROFORMYLATED AND HYDROGENATED FATTY ALKYL ESTER COMPOSITIONS" by
George Frycek, Shawn Feist, Zenon Lysenko, Bruce Pynnonen and Tim
Frank, filed Jun. 20, 2008, application number PCT/US08/67585,
published as WO 2009/009271. The use of NOBP made using a monomer
not rich in mono-hydroxy functional fatty acid alkyl esters results
in a highly crosslinked system that can lead to loss in mechanical
properties. Sealant compositions require polymers with high
elongation, and thus the preference for monol-rich monomer NOBP.
Mono-functional monomers, such as those of formula (I), are used to
synthesize the polyol.
[0023] The monol-rich monomer NOBP may be derived by first
hydroformylating and hydrogenating the fatty alkyl esters or acids,
followed by purification to obtain monol rich monomer.
Alternatively, the fatty alkyl esters or acids may first be
purified to obtain mono-unsaturated rich monomer and then
hydroformylated and hydrogenated.
[0024] In one embodiment the NOBP is made from a monomer derived
using epoxidation and ring opening of the natural oil fatty acids
or methyl ester fatty acids, as described in WO 2009/058367 and WO
2009/058368.
[0025] The polyol is formed by reaction of the monomer with an
appropriate initiator compound to form a polyester or
polyether/polyester polyol. Such a multistep process is commonly
known in the art, and is described, for example, in PCT publication
Nos. WO 2004/096882 and 2004/096883. The multistep process can
result in the production of a polyol with both hydrophobic and
hydrophilic moieties, which results in enhanced miscibility with
both water and conventional petroleum-based polyols.
[0026] The initiator for use in the multistep process for the
production of the natural oil derived polyols may be any initiator
used in the production of conventional petroleum-based polyols.
Preferably the initiator is selected from the group consisting of
neopentylglycol; 1,2-propylene glycol; trimethylolpropane;
pentaerythritol; sorbitol; sucrose; glycerol; aminoalcohols such as
ethanolamine, diethanolamine, and triethanolamine; alkanediols such
as 1,6-hexanediol, 1,4-butanediol; 1,4-cyclohexane diol;
1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol,
2,5-hexanediol; ethylene glycol; diethylene glycol, triethylene
glycol; bis-3-aminopropyl methylamine; ethylene diamine; diethylene
triamine; 9(1)-hydroxymethyloctadecanol,
1,4-bishydroxymethylcyclohexane;
8,8-bis(hydroxy-methyl)tricyclo[5,2,1,0.sup.2,6]decene; Dimerol
alcohol (36 carbon diol available from Henkel Corporation);
hydrogenated bisphenol; 9,9(10,10)-bishydroxymethyloctadecanol;
1,2,6-hexanetriol and combination thereof. Preferably the initiator
is selected from the group consisting of glycerol; ethylene glycol;
1,2-propylene glycol; trimethylolpropane; ethylene diamine;
pentaerythritol; 1,4-cyclohexanedimethanol, diethylene triamine;
sorbitol; sucrose; or any of the aforementioned in which at least
one of the alcohol or amine groups present has been reacted with
ethylene oxide, propylene oxide or mixture thereof; and
combinations thereof. Preferably, the initiator is glycerol,
trimethylolpropane, pentaerythritol, 1,4-cyclohexanedimethanol,
sucrose, sorbitol, and/or mixture thereof. Other initiators include
other linear and cyclic compounds containing an amine. Exemplary
polyamine initiators include ethylene diamine, neopentyldiamine,
1,6-diaminohexane; bisaminomethyltricyclodecane;
bisaminocyclohexane; diethylene triamine; bis-3-aminopropyl
methylamine; triethylene tetramine various isomers of toluene
diamine; diphenylmethane diamine; N-methyl-1,2-ethanediamine,
N-methyl-1,3-propanediamine, N,N-dimethyl-1,3-diaminopropane,
N,N-dimethylethanolamine, 3,3'-diamino-N-methyl-dipropylamine,
N,N-dimethyldipropylenetriamine and aminopropyl-imidazole.
[0027] In one embodiment the initiators are alkoxylated with
ethylene oxide, propylene oxide, or a mixture of ethylene and at
least one other alkylene oxide to give an alkoxylated initiator
with a molecular weight between 200 and 6000, preferably between
500 and 5000. In one embodiment the initiator has a molecular
weight of 550, in another embodiment the molecular weight is 625,
and in yet another embodiment the initiator has a molecular weight
of 4600.
[0028] In one embodiment at least one initiator is a polyether
initiator having an equivalent weight of at least 400 or an average
at least 9.5 ether groups per active hydrogen group, and such
initiators are described in WO 2009/117630.
[0029] The ether groups of the polyether initiator may be in
poly(alkylene oxide) chains, such as in poly(propylene oxide) or
poly(ethylene oxide) or a combination thereof. In one embodiment
the ether groups may be in a diblock structure of poly(propylene
oxide) capped with poly(ethylene oxide).
[0030] In one embodiment the NOBP is a polyol which comprises at
least two natural oil moieties separated by a molecular structure
having at least about 19 ether groups or separated by a polyether
molecular structure having an equivalent weight of at least about
480.
[0031] In one embodiment, a NOBP is made with an alkoxylated
initiator or combination of alkoxylated initiators having an
average equivalent weight of between 400 and 3000 per active
hydrogen group. The average equivalent weight can be from a lower
limit of 400, 450, 480, 500, 550, 600, 650, 700, 800, 900, 1000,
1200, or 1300 to an upper limit of 1500, 1750, 2000, 2250, 2500,
2750, or 3000 per active hydrogen group.
[0032] Thus, in this embodiment, at least two of the natural oil
based monomers are separated by a molecular structure having an
average molecular weight of between 1250 Daltons and 6000 Daltons.
The average molecular weight can be from a lower limit of 1250,
1500, 1750, 2000, 2250, 2500, 2750, or 3000 Daltons to an upper
limit of 3000, 3500, 4000, 4500, 5000, 5500, or 6000 Daltons.
[0033] To form the polyether initiator, the active hydrogen groups
may be reacted with at least one alkylene oxide, such ethylene
oxide or propylene oxide or a combination thereof; or a block of
propylene oxide followed by a block of ethylene oxide, to form a
polyether polyol by means within the skill in the art. The
polyether initiator may be used as an initiator for reaction with
at least one natural oil based monomer. Alternatively the initiator
is reacted by means within the skill in the art to convert one or
more hydroxyl groups to alternative active hydrogen groups, such as
is propylene oxide.
[0034] Thus, in one embodiment the natural oil based polyol may
comprise at least two natural oil moieties separated by a molecular
structure having at least 19 ether groups or having an equivalent
weight of at least 400, preferably both. When the polyether
initiator has more than 2 active hydrogen groups reactive with the
natural oil or derivative thereof, each natural oil moiety is
separated from another by an average of at least 19 ether groups or
a structure of molecular weight of at least 400, preferably
both.
[0035] The functionality of the resulting natural oil based polyols
is above 1.5 and generally not higher than 6. In one embodiment the
functionality is below 4. The hydroxyl number of the natural oil
based polyols may be below 300 mg KOH/g, preferably between 20 and
300, preferably between 20 and 200. In one embodiment, the hydroxyl
number is below 100.
[0036] Polyisocyanates
[0037] Any of numerous polyisocyanates, advantageously
diisocyanates, can be used to make the NOBP polyurethane. In one
embodiment the polyisocyanate is at least one of diphenylmethane
diisocyanate ("MDI"), polymethylene polyphenylisocyanate ("PMDI"),
paraphenylene diisocyanate, naphthylene diisocyanate, liquid
carbodiimide-modified MDI and its various derivatives, isophorone
diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, toluene
diisocyanate ("TDI"), particularly the 2,6-TDI isomer, as well as
various other aliphatic and aromatic polyisocyanates that are
well-established in the art.
[0038] Sealant Composition
[0039] The NOBP is used to synthesize polyurethane sealant
composition systems. Two-component polyurethane systems comprise a
first component of a polyisocyanate and/or an isocyanate-terminated
prepolymer with a second component of a low-molecular-weight polyol
and/or urethane-modified polyol having molecular weight typically
of less than 10,000, and are mixed immediately before application,
and applied to a base material to be cured.
[0040] Typically the sealant composition of this invention
comprises at least 20, more typically at least 25 and even more
typically at least 30, wt % monol-rich monomer NOBP-based
polyurethane. The sealant compositions of this invention typically
also comprise at least one of a plasticizer, filler, pigment,
antioxidant, rheology modifier, cure catalyst, UV stabilizer,
adhesion promoter, cure accelerator, moisture scavenger, dye,
surfactant, solvent and biocide.
[0041] Representative fillers include but are not limited to one or
more of precipitated and colloidal calcium carbonates which have
been treated with compounds such as stearic acid or stearate ester;
reinforcing silicas such as fumed silicas, precipitated silicas,
silica gels and hydrophobized silicas and silica gels; crushed and
ground quartz, alumina, aluminum hydroxide, titanium hydroxide,
diatomaceous earth, iron oxide, carbon black, graphite, mica, talc,
and the like. Fillers, if present, typically comprise 20 to 80,
more typically 30 to 70 and even more typically 40 to 60, wt % of
the sealant composition.
[0042] The sealant composition typically comprises, if present, 0.1
to about 10 wt % of a glass adhesion promoter such as a silane,
e.g., an aminopropyl-trimethoxysilane, mercaptopropyl
trimethoxysilane or glycidoxypropyl trimethoxysilane. The sealant
composition typically comprises, if present, 1 to 30, more
typically 2 to 25 and even more typically 3 to 20 wt % of a
plasticizer such as an alkylbenzyl phthalate (e.g., alkyl is
octyl), chlorinated paraffin, seed oil or seed oil derivative, and
the like.
[0043] The sealant composition can also include one or more
alkoxysilanes as adhesion promoters. Useful adhesion promoters
include N-2-aminoethyl-3-aminopropyl-triethoxysilane,
gamma-aminopropyltriethoxysilane,
gamma-aminopropyltrimethoxysilane, aminopropyltrimethoxysilane,
bis-gamma-trimethoxysilypropyl)amine,
N-phenyl-gamma-aminopropyltrimethoxysilane,
triaminofunctionaltrimethoxysilane and
gamma-aminopropyl-methyldiethoxysilane. The sealant composition
typically comprises, if present, 0.1 to 10, more typically 0.5 to 8
and even more typically 1 to 6 wt % of the adhesion promoter.
[0044] The sealant compositions can also include one or more
surfactants, typically a non-ionic surfactant, such as polyethylene
glycol, polypropylene glycol, ethoxylated castor oil, oleic acid
ethoxylate, alkylphenol ethoxylates, copolymers of ethylene oxide
and propylene oxide, copolymers of silicones and polyethers,
copolymers of silicones and ethylene oxide and/or propylene oxide.
The sealant composition typically comprises, if present, 0.1 to 10,
more typically 0.5 to 8 and even more typically 1 to 6 wt % of the
surfactant.
[0045] The sealant compositions may also include at least one chain
extender. For purposes of the embodiments of the invention, a chain
extender is a material having two isocyanate-reactive groups per
molecule and an equivalent weight per isocyanate-reactive group of
less than 400, preferably less than 300 and especially from 31-125
Daltons. Representative of suitable chain-extending agents include
polyhydric alcohols, aliphatic diamines including
polyoxyalkylenediamines, and mixtures thereof. The isocyanate
reactive groups are preferably hydroxyl, primary aliphatic amine or
secondary aliphatic amine groups. The chain extenders may be
aliphatic or cycloaliphatic, and are exemplified by triols,
tetraols, diamines, triamines, aminoalcohols, and the like.
Representative chain extenders include ethylene glycol, diethylene
glycol, 1,3-propane diol, 1,3- or 1,4-butanediol, dipropylene
glycol, 1,2- and 2,3-butylene glycol, 1,6-hexanediol,
neopentylglycol, tripropylene glycol, 2-ethyl hexanediol, ethylene
diamine, 1,4-butylenediamine, 1,6-hexamethylenediamine,
1,5-pentanediol, 1,6-hexanediol, 1,3-cyclohexandiol,
1,4-cyclohexanediol; 1,3-cyclohexane dimethanol, 1,4-cyclohexane
dimethanol, N-methylethanolamine, N-methyliso-propylamine,
4-aminocyclohexanol, 1,2-diaminotheane, 1,3-diaminopropane,
hexylmethylene diamine, methylene bis(aminocyclohexane), isophorone
diamine, 1,3- or 1,4-bis(aminomethyl)cyclohexane,
diethylenetriamine, and mixtures or blends thereof. The chain
extenders may be used in an amount from 0.5 to 20, especially 1 to
10 parts by weight per 100 parts by weight of the polyol
component.
[0046] In addition to the above described polyols, the polyol
compositions may also include other ingredients such as
preservatives and antioxidants.
[0047] Catalysts typically used in the one and two component
sealant compositions of this invention include those known to be
useful for facilitating polyurethane production. The catalysts
include metal and non-metal catalysts. Examples of the metal
portion of the metal catalysts useful in the present invention
include tin, titanium, zirconium, lead, iron cobalt, antimony,
manganese, bismuth and zinc compounds. In one embodiment the tin
compounds useful for facilitating crosslinking in the sealant
compositions include: tin compounds such as dibutyltindilaurate,
dibutyltindiacetate, dibutyltindimethoxide, tinocto ate,
isobutyltintriceroate, dibutyltinoxide, solubilized dibutyl tin
oxide, dibutyltin bis-diisooctylphthalate, bis-tripropoxysilyl
dioctyltin, dibutyltin bis-acetylacetone, silylated dibutyltin
dioxide, carbomethoxyphenyl tin tris-uberate, isobutyltin
triceroate, dimethyltin dibutyrate, dimethyltin di-neodecanoate,
triethyltin tartarate, dibutyltin dibenzoate, tin oleate, tin
naphthenate, butyltintri-2-ethylhexylhexoate, and tinbutyrate, and
the like.
[0048] The sealant compositions of this invention may include at
least one other polymer such as polyethylene, e.g., low density
polyethylene (LDPE), very low density polyethylene (VLDPE), linear
low density polyethylene (LLDPE) and high density polyethylene
(HDPE); polypropylene (PP); polyisobutylene (PIB); polyvinyl
acetate (PVAc); polyvinyl alcohol (PVOH); polystyrene;
polycarbonate; polyester such as polyethylene terephthalate (PET),
polybutylene terephthalate (PBT), polyethylene napthalate (PEN),
and glycol-modified polyethylene terephthalate (PETG);
polyvinylchloride (PVC); polyvinylidene fluoride; acrylonitrile;
butadiene styrene (ABS); polymethylmethacrylate (PMMA); polyamide
(nylon), polymethylpentene; polyimide (PI); polyetherimide (PEI);
polyether ether ketone (PEEK); polysulfone; polyether sulfone;
ethylene chlorotrifluoroethylene; polytetrafluoroethylene (PTFE);
cellulose acetate; cellulose acetate butyrate; ionomers (e.g.,
Surtyn.TM.); polyphenylene sulfide (PPS); styrene-maleic anhydride;
modified polyphenylene oxide (PPO), and the like. The optional
polymer or polymers can be elastomeric in nature, examples of which
include but are not limited to, ethylene-propylene rubber (EPDM),
polybutadiene, polychloroprene, polyisoprene,
styrene-butadiene-styrene (SBS), styrene-ethylene-butadiene-styrene
(SEBS), polymethylphenyl siloxane (PMPS), and the like. These
optional polymers can be blended either alone or in combinations or
used in the form of copolymers, e.g. polycarbonate-ABS blends,
polycarbonate polyester blends, grafted polymers such as silane
grafted polyethylenes, and the like. If present, the optional
polymer is typically at least one of LDPE, VLDPE, LLDPE, and HDPE.
If present, the optional polymer typically comprises 0.1 to 50,
more typically 1 to 40, wt % of the sealant composition.
[0049] The sealant compositions of this invention are prepared by
procedures well known in the art, e.g., melt blending, extrusion
blending, solution blending, dry mixing, etc., in or out of the
presence of moisture, to provide a substantially homogeneous
mixture. The sealant compositions of this invention are used in the
same manner as known sealants for IG units.
Insulated Glass Unit
[0050] Insulated glass (IG) units are well known, and FIG. 1a of WO
2009/060199 is illustrative. The IG unit is of known and
conventional construction, and it includes two panes maintained in
a parallel, spaced-apart relationship by one or more spacer bars,
thus forming a cavity between the panes. A primary gas sealant is
present between each spacer bar and each pane, adjacent to the
cavity. A secondary gas sealant is present between each pane and
each spacer bar, not adjacent to the cavity. The sealant
composition of this invention can be either or both the primary and
secondary gas sealants although it is typically the secondary
sealant. The cavity between the panes is filled with an insulating
gas or gases such as air, carbon dioxide, sulfur hexafluoride,
nitrogen, argon, krypton, xenon, and the like. A glazing bead is
typically positioned between the panes and the window frame. The
panes can be fabricated from any of a variety of materials such as
glass, e.g., clear float glass, annealed glass, tempered glass,
solar glass, tinted glass and low energy glass; acrylic resin;
polycarbonate resin; and the like.
[0051] The cured sealant composition of this invention provides
improved gas barrier characteristics and moisture leakage
characteristics relative to known and conventional gas sealants. As
a result, the cured sealant composition of this invention provides
for longer in-service performance of insulated glass units of all
manner of construction.
[0052] Although the sealant compositions of this invention can
serve as the primary gas sealant, typically the primary gas sealant
comprises any one of a number of polymeric materials known in the
art as useful for serving as a primary sealant including, but not
limited to, rubber base materials such as polyisobutylene, butyl
rubber, polysulfide, EPDM rubber, nitrile rubber, and the like.
Other useful materials include, polyisobutylene/polyisoprene
copolymers, polyisobutylene polymers, brominated olefin polymers,
copolymers of polyisobutylene and para-methylstyrene, copolymers of
polyisobutylene and brominated para-methylstyrene, butyl
rubber-copolymer of isobutylene and isoprene, ethylene-propylene
polymers, polysulfide polymers, polyurethane polymers, styrene
butadiene polymers, and the like. In addition, the sealant
composition of this invention can be used as the primary gas
sealant.
[0053] The primary gas sealant member can be fabricated from a
material such as polyisobutylene which has very good sealing
properties. The glazing bead is a sealant that is sometimes
referred to as the glazing bedding and can be provided in the form
of a silicone or butyl rubber. Desiccant can be included in the
continuous spacer to remove moisture from the insulating gas
occupied cavity or space between the panes. Useful desiccants are
those that do not adsorb the insulating gas/gases filling the
interior of the insulated glass unit.
[0054] The following examples are illustrative of certain
embodiments of the present invention. All parts and percentages are
based on weight except as otherwise indicated.
Specific Embodiments
EXAMPLE 1
[0055] NOBP-A (82.5 g, a soybean oil based polyol) is prepared
according to Example 7 of WO 2009/117630. The molar ratio of
monomer to initiator is 6:1. NOBP-A has a hydroxyl number of 27,
and is blended with 1,4-butanediol (2.1 g) and sufficient
dibutyltindilaurate to obtain 100 ppm of this catalyst. To this
mixture ISONATE 143L (12.8 g, a polycarbodiimide-modified
diphenylmethane diisocyanate available from The Dow Chemical
Company) is added and vigorously mixed. The resulting blend is
placed in a metal spacer between two metal plates and pressed at
50.degree. C. to form a homogenous plaque or film. This resulting
film has a tensile strength of 216 psi and an ultimate elongation
of 322%.
EXAMPLE 2
[0056] NOBP-A (82.5 g) is blended with 2-ethyl-1,3 hexanediol (3.0
g) and sufficient dibutyltindilaurate to obtain 100 ppm of this
catalyst. To this mixture ISONATE 143L (11.9 g) is added and the
vigorously mixed. The resulting blend is placed in a metal spacer
between two metal plates and pressed at 50.degree. C. to form a
homogenous plaque or film. This resulting film has a tensile
strength of 2103 psi and an ultimate elongation of 367%.
EXAMPLE 3
[0057] NOBP-B is made by combining monol-rich natural oil monomer
(1351.76 g) and 1,4-cyclohexanedimethanol (48.02 g). The monol-rich
natural oil monomer has an average of 1.0 hydroxyls per fatty acid
and is derived from fractionated fatty acids yielding a
distribution of about 1 weight percent (wt %) saturated monomer,
about 93 wt % mono-hydroxy monomer, about 3 wt % di-hydroxyl
monomer, and about 1 wt % cyclic ethers. The monomer distribution
is obtained using the method disclosed in co-pending application
published as WO 2009/009271. The mixture is heated and held between
70.degree. C. and 90.degree. C. for 30 minutes with stirring and
nitrogen stripping in a three neck flask. Stannous octoate (0.88 g)
is then added to the mixture and the temperature is increased to
195.degree. C. The mixture is stirred at the reaction temperature
of 195.degree. C. with nitrogen stripping for 6 hours and then
cooled to room temperature. The resulting NOBP-B polyol is then
dispensed in air through the reactor bottom drain valve and stored
in a HDPE plastic container.
EXAMPLE 4
[0058] NOBP-B (82.5 g) is blended with of 1,4-butanediol (2.5 g)
and sufficient dibutyltindilaurate to obtain 100 ppm of this
catalyst. To this mixture ISONATE 143L (15.1 g) is added and
vigorously mixed. The resulting blend is placed in a metal spacer
between two metal plates and pressed at 50.degree. C. to form a
homogenous plaque or film. This resulting film has a tensile
strength of 362 psi and an ultimate elongation of 308%.
EXAMPLE 5
[0059] NOBP-B (10 g) is blended with 1,4-butanediol (0.3 g),
Palatinol N (3.0 g, available from BASF), Super-Pflex 200 (8.5 g,
available from Minerals Technologies Incorporated), Ultra-Pflex
(4.0 g, available from Minerals Technologies Incorporated),
Cab-O-Sil TS-720 fumed silica (0.3 g, available from Cabot Corp.),
and sufficient dibutyltindilaurate to obtain 100 ppm of this
catalyst. ISONATE 143L (1.8 g) is added and vigorously mixed. The
resulting blend is placed in a metal spacer between two metal
plates and pressed at 50.degree. C. to form a homogenous plaque or
film. This resulting film has a tensile strength of 386 psi and an
ultimate elongation of 427%.
EXAMPLE 6
[0060] A homogenous plaque or film is made as in Example 5, but
with 2-ethyl-1,3-hexanediol (0.3 g) as a chain extender instead of
1,4-Butanediol (0.3 g). This resulting film has a tensile strength
of 354 psi and an ultimate elongation of 574%.
EXAMPLE 7
[0061] ISONATE 143L (64.5 grams) is added to NOBP-B (35.5 g) and
the mixture is heated under nitrogen with stirring at 75.degree. C.
for 3 hours to form a prepolymer. The measured percent NCO of the
resulting prepolymer is 20.1. A portion of the prepolymer. (1.7 g)
is vigorously mixed with a blend of NOBP-B (10 g) 1,4-butanediol
(0.3 g), Palatinol N (3.0 g), Super-Pflex 200 (8.5 g), Ultra-Pflex
(4.0 g), Cab-O-Sil TS-720 fumed silica (0.3 g), and sufficient
dibutyltindilaurate to obtain 100 ppm of this catalyst. The
resulting blend is placed in a metal spacer between two metal
plates and pressed at 50.degree. C. to form a homogenous plaque or
film. This resulting film has a tensile strength of 466 psi and an
ultimate elongation of 316%.
COMPARATIVE EXAMPLE A
[0062] The polyol in Poly bd.RTM. Resin R-45HTLO (88.9 g, available
from the Sartomer Company, Inc.) is blended with
2-ethyl-1,3-hexanediol (2.5 g) and sufficient dibutyltindilaurate
to obtain 300 ppm of this catalyst. To this mixture, ISONATE 143L
(14.3 g) is added and vigorously mixed. The resulting blend is
placed in a metal spacer between two metal plates and pressed at
50.degree. C. to form a homogenous plaque or film. This resulting
film has a tensile strength of 248 psi and an ultimate elongation
of 481%.
Unfilled Systems
[0063] DMTA
[0064] The polyurethane polymer of Example 3 is used for an
insulated glass sealant composition. FIGS. 1A and 1B show that the
properties of polyurethane prepared with monol-rich monomer NOBP
are comparable to polybutadiene-based polyurethane (control).
Dynamic mechanical thermal analysis (DMTA) measurements are made
using a commercially available DMA instrument such as that
available from TA Instruments under the trade designation RSA III,
using a rectangular geometry in tension. Specimens are ramped from
an initial temperature of -90.degree. C. to a final temperature of
250.degree. C. or until the sample fails. The DMTA plot of FIG. 1A
(polybutadiene based-PU) shows a dual transition at -50.degree. C.
and 0.degree. C. However the purified NOBP-based PU (FIG. 1B) shows
a single transition at --47.degree. C. This single transition is
advantageous during the thermal cycles that IG sealants must
withstand.
[0065] Mechanical Properties
[0066] The mechanical properties of the polybutadiene- and the
NOBP-based materials of Example 3 are compared before and after
water absorption. The films are cut into dog bones and then
immersed in deionized water for 24 hours or in boiling water for 1
hour. After exposure the films are dried with a tissue and the
tensile property are measured in accordance to ASTM D1708 on the
same day, typically within the first couple of hours. The control
sample lost about 25% of its elongation as shown in FIG. 2A as well
as tensile strength as shown in FIG. 2B. However the monol-rich
monomer NOBP-based material shows only marginal loss which is
within the error of the measurements techniques. In the water
absorption test the samples performed comparably.
[0067] Weathering Properties
[0068] The polymer films are aged for thirty days using alternate
cycles of UV exposure at 50.degree. C. followed by 100% relative
humidity for 4 hours each. The results as shown in FIG. 3 indicate
that the control sample performed very poorly compared to the
purified NOBP-based samples. The hydrophobicity of the monol-rich
monomer NOBP-based polyurethane proved advantageous in the
weathering experiments.
[0069] MVTR and OTR
[0070] The polymer used as a secondary seal for insulating glass
may also act as a moisture vapor or gas barrier resulting in
further improvement in performance and service life of the IG
units. Polybutadiene-based polyurethane shows good performance
(FIG. 4A) when it comes to moisture vapor transmission rate (MVTR).
However further improvement is needed in gas permeation rates as
measured by oxygen transmission rate (OTR). Monol-rich monomer
NOBP-based polyurethane (Example 3) shows comparable results (FIG.
4A) with the control. However the monol-rich monomer NOBP-based
polyurethane shows an improvement in OTR measurements (FIG.
4B).
[0071] Fully Formulated Systems
[0072] The system with fillers and other additives showed
comparable DMTA properties, but improvement in tensile and
elongation properties. However the advantage of using the
monol-rich monomer NOBP polyurethane in this sealant is its low
viscosity which leads to lowering the actual amount of plasticizer
in the final sealant.
[0073] Although the invention has been described with certain
detail through the preceding specific embodiments, this detail is
for the primary purpose of illustration. Many variations and
modifications can be made by one skilled in the art without
departing from the spirit and scope of the invention as described
in the following claims.
* * * * *